Magazine Archive

Home -> Magazines -> Issues -> Articles in this issue -> View

Yamaha RM804 Mixer

When it comes to choosing a mixer for recording, the range of products available today can seem bewildering to the uninitiated. It is too easy for the recordist to be swayed by the well-known big names and overlook the 'dark horses' of the mixer world, who can sometimes provide the potential buyer with an equally good product.

Yamaha have been a bit of a 'dark horse' in the past as far as recording-based equipment was concerned. That is until the introduction of their excellent MT44 four track recorder which firmly placed them on the map. This commitment to the recording fraternity continues with their 'RM' range of mixing desks, designed specifically for recording purposes; and it is their bottom of the range RM804 unit which we have chosen to look at this month.


As its name implies, this is an 8 input, 4 output stereo mixer. In terms of appearance the unit would not look too out of place lying next to the hi-fi tower in your living room, although the black facia and rosewood veneer finish do have an 'old-fashioned' look about them. The small size (19¼"W x 20"D x 6⅜"H) causes one to draw immediate comparisons with Tascam's budget mixers, but the comparison ends there; the Yamaha is a much easier beast to work with. Space is always at a premium in any studio, and so the convenient size must be seen as a help in this respect.

Layout of the facia is standard with the eight input channels to the left/centre and master/monitor section to the right. Above these is the angled meter bridge containing VU meters - one for each group output, and stereo output (6 in all). Although VUs come second to peak programme meters (PPMs) in my book, the Yamaha does offer a compromise by incorporating a fast-acting Peak LED indicator on each VU meter (as on Revox tape recorders), to give at least some warning of transient distortion before all-out 'Clipping' occurs. 0VU on these meters, by the way, gives a real output level reading of -10 dB, making the RM804 fully compatible with budget recording devices eg. Fostex, Tascam gear.

In use, the VU meters were slightly annoying to work with in dark conditions as they weren't as clearly lit as they could have been, but this would not be a real problem either in daylight or in a well-lit studio/room, it's just that I personally prefer dark, moody background lighting when I'm recording myself.

Bearing this in mind, the Yamaha scored well in terms of layout; it's simple to find your way around in the dark and with enough space left between each channels' controls to actually let your fingers grip a knob without scraping your knuckles on the controls next to you! The vinyl arm rest seemed a bit of a luxury, however, as the mixer simply is not deep enough to warrant its inclusion, in practice.

Channel Layout

The eight input channels are identical but rather unconventional in terms of their function layout. Each channel is effectively an input and output routing system in its own right, which is exactly how it will be used if an 8-track tape recorder is utilised, as each input channel feeds a tape track and also controls the signal coming back off tape during stereo mixdown.

Usually the signals would be sent to the recorder via the group outputs, but this is only possible on the RM804 when using a 4-track machine, without the need for re-patching your connecting leads, as the mixer only has four individual mixing busses apart from the stereo buss which would normally feed the monitor speakers and/or 2-track master recorder.

Somewhat unusually, the routing pushbuttons used to assign the input channel to an output buss are situated at the head of each channel instead of above the fader. The Pan pot below them adjusts the relative output level sent to the selected busses. Fully left selects busses 1 & 3, right for 2 & 4 and centre sends an equal amount of signal to all four busses. This system worked well with no significant breakthrough of signal on undesired busses.

The signal feeding the input channel can come from three sources: microphone level inputs via the rear panel female XLR sockets, line level inputs via the same sockets or from tape via the phono connections; and a Mic/Line/Tape button selects the required source. The variable Input Gain control, in conjunction with its peak reading LED, can then be used to optimise recording levels and this is best set with the channel fader around ¾ of its travel to ensure a usable fader range when mixing.

The gain range was plenty to handle microphones, but I was unable to test the line level setting due to the fact that the mixer was not fitted with jack inputs! This appears to be an oversight on Yamaha's part. It is not possible, for example, to plug the output of a synth or drum machine directly into the RM804 without either (1) cutting off the jackplug from the synth lead and soldering on an XLR connector or (2) using a jack to phono, or jack to XLR adaptor.

Are we then to believe that all line level connections will be made only via the balanced XLR connectors? If so, why has the semi-professional line level of -10 dB operation been chosen? This is but one of the anomalies that come to light upon thorough investigation of the rear panel connections (of which more later).

A simple choice of fixed frequency High, Mid and Low equalisation is provided on each input channel, giving up to 15 dB of cut or boost to signals in each band. Unfortunately, there appears to be a slight discrepancy between what we in the West call 'Mid' and what the Japanese call 'Mid', as the chosen centre frequency for this control is 2 kHz! Now this would not cause undue discomfort to any user within the context of a five band EQ section, say, where a 2 kHz tone control would actually be quite useful, for it coincides with the most sensitive range of the human ear.

However, when set alongside the 100 Hz and 10 kHz turnover frequencies of the accompanying Low and High controls (which are not sweepable), it leaves an almighty wide range of frequencies over which you have absolutely no control whatsoever when using the RM804. This can only be described as disappointing on a mixer of this calibre.

The final controls on the Yamaha's input channels are unusual in their arrangement. 'Echo' is a dedicated auxiliary send which governs the level of the signal sent to an external echo (or any other signal processor) unit, and 'Stereo' fulfills a similar function, but sends the signal to the main stereo output buss and thus to the headphones/monitor speakers. In effect, the Stereo control offers a similar function to a 'foldback' control. However, the signals sent to the echo unit and/or stereo outputs can only be post fader or direct from the tape tracks, which precludes the use of the aforementioned Stereo send control for any sort of pre-fade listen (PFL) function. The advantage of this separate Stereo control is perhaps the opportunity of having different signal levels going to the Left/Right outputs and group outputs, which is possible to achieve on any mixer with individual group output faders anyway.

A Stereo Pan knob enables the off-tape or input signals to be placed within the stereo image, during initial recording or final mixdown. The channel features are completed by a beautifully smooth action fader with a wide, concave top for convenient level adjustment. Rather surprisingly, this fader only controls the level of signals feeding the group outputs and not the stereo outputs, which is the reason for the separate Stereo level knob.

What this means, in practice, is that the only way to use the RM804 as a basic 8 into 2 stereo mixer, is by using the rotary Stereo level control (instead of faders) to alter your channel levels. Have you ever tried turning four rotary pots simultaneously? It's well nigh impossible! It certainly isn't conducive to easy recording...

Master Section

All monitoring and master output controls are contained within the right hand area of the facia. Above the single red ganged Master Stereo fader (a thoughtful feature) is the master Echo Send level control and four pink-coloured rotary knobs labelled 'PGM 1-4.' According to the RM804 brochure these controls "perform the same function as the 'submaster faders' on some mixers." This is an arguable statement: the fact that they are rotary pots and not faders on the RM804, prevents you from achieving a smooth submix if any fading of levels is involved!

Controls to set the master level of the Left and Right Echo Return signals are included in this section, along with pushbuttons to route the above signals to the four group busses and/or stereo outputs. If the returned signal is connected, via the ¼" jack socket on the rear panel, to the Echo Return Left input only, the signal will be routed to all four busses (instead of only to 1 & 3 as for normal operation).

The remaining controls in this section deal with the monitoring. The buttons marked 1, 2, 3, 4, Stereo and 2 Track In determine which source signal will be sent to the Monitor outputs, and thus to the control room speakers (if connected). They also feed the stereo headphone socket which is well positioned at the bottom right of the front panel. Unfortunately, these headphones have to share the Monitor level control, which affects both the volume of the signals feeding the speakers as well as the headphones. It goes without saying that there will be times when you'll need a totally separate feed for each, so why have Yamaha adopted this system?


These are all to be found on the rear panel, logically laid out and well identified. They (theoretically) provide enough scope to accommodate either 4 or 8-track tape machines, as well as a feed to a stereo master recorder for making your final stereo mix.

Apart from the Mic/Line XLR inputs already discussed, each channel has a phono Tape Input, for permanent connection to the outputs of a multitrack machine, and a Direct (post-fader) Output for connection to the multitrack's inputs. Both operate at -10 dB levels, and would be the preferred means of linking up an 8-track recorder to the mixer.

A -10 dB Insert facility is available on each channel, for patching in effects units directly to a specific channel, which does compensate for the lack of multiple auxiliary sends, slightly. Yamaha have chosen to use phono connectors for this, however, and jack sockets for the Echo Send and Return connections, which seems a strange choice to me. Few signal processors utilise phono connectors these days, most employ jacks. Even if they did use phonos, why put jacks on the Echo Send, if this output is supposed to be used with similar types of effects? Jack sockets all round would have been a much better choice.

Phono connectors are also used for the four group outputs (which would be best used to feed a 4-track recorder, for example), and for the Sub In sockets. These are designed to connect with a second mixer to increase the number of input channels, but could also be used to patch in an external effect, but without any individual level control of the incoming signal other than on the effects device itself.

Jack outputs for Monitor L/R enable the stereo buss mix to feed an amplifier and thus a pair of speakers. The last four connections allow a stereo recorder to be connected so that a stereo mix can be recorded and replayed simply by selecting the 2 Track In button on the monitor section.


What at first glance appears to be a well-designed 8/4/2 mixer, soon turns out to be a somewhat limited and limiting unit. It suffers in terms of functions but what it does do, it does well. The noise figures and crosstalk, for example, are low indeed, and to be commended.

However, most recording enthusiasts will probably buy a piece of equipment depending upon the facilities it provides and not necessarily on quality. At a retail selling price of £738, the RM804 does lack certain functions; submix faders, PFL, only one auxiliary and an unusable Mid EQ control. To me, the RM804 looks to be a mixer in search of a market, it disappoints on many counts and does not do the Yamaha name justice.

Further details from Yamaha, (Contact Details).

Also featuring gear in this article

Yamaha RM804
(ES May 84)

Browse category: Mixer > Yamaha

Previous Article in this issue

UB40 In the Studio

Next article in this issue

Phono Guide

Home & Studio Recording - Copyright: Music Maker Publications (UK), Future Publishing.


Home & Studio Recording - May 1984

Donated & scanned by: Mike Gorman, Gab

Gear in this article:

Mixer > Yamaha > RM804

Review by Ian Gilby

Previous article in this issue:

> UB40 In the Studio

Next article in this issue:

> Phono Guide

Help Support The Things You Love

mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.

If you value this resource, you can support this project - it really helps!

Donations for August 2022
Issues donated this month: 0

New issues that have been donated or scanned for us this month.

Funds donated this month: £136.00

All donations and support are gratefully appreciated - thank you.

Magazines Needed - Can You Help?

Do you have any of these magazine issues?

> See all issues we need

If so, and you can donate, lend or scan them to help complete our archive, please get in touch via the Contribute page - thanks!

Please Contribute to mu:zines by supplying magazines, scanning or donating funds. Thanks!

Monetary donations go towards site running costs, and the occasional coffee for me if there's anything left over!

Small Print

Terms of usePrivacy